package com.example.yls.demoa;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

/**
 * Created by yls on 2018/11/26.
 */

public class StudbOpenHelper extends SQLiteOpenHelper {
    public StudbOpenHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
        super(context, name, factory, version);
    }

    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase) {
        Log.e("StudbOpenHelper","OnCreate");
        String sql="create table student " +
                "(stuno varchar(20),name varchar(20),age int)";
        sqLiteDatabase.execSQL(sql);

    }

    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int oldVersion, int newVersion) {
        if(oldVersion==1 && newVersion==2){
            String sql="alter table add column phone varchar(20)";
            sqLiteDatabase.execSQL(sql);
        }
        if(oldVersion==2 && newVersion==3){
            String sql="create table score (stuno varchar(20),score int)";
            sqLiteDatabase.execSQL(sql);
        }
    }
}
